Pile driving method and apparatus

ABSTRACT

A PILE DRIVING METHOD AND APPARATUS WHEREIN A BAFFLE IS PROVIDED IN A PIPE OR OTHER HOLLOW PILE, AND A PRESSURE DIFFERENTIAL IS CREATED ACROSS THE BAFFLE TO MOVE OR VIBRATE THE PILE FOR EITHER DRIVING THE PILE INTO THE GROUND OR REMOVING IT FROM THE GROUND.

Nov. 16, 1971 J T MALLARD PILE DRIVING METHOD AND APPARATUS Filed NOV. 17, 1969 United States Patent O 3,620,026 PILE DRIVING METHOD AND APPARATUS .I T. Mallard, 10203 Chadwick, Houston, Tex. 77029 Filed Nov. 17, 1969, Ser. No. 877,362 Int. Cl. E02d 7/18, 7/20 U.S. Cl. 61-46.5 5 Claims ABSTRACT F THE DISCLOSURE A pile driving method and apparatus wherein a baille is provided in a pipe or other hollow pile, `and a pressure differential is created across the baille to move or vibrate the pile for either driving the pile into the ground or removing it from the ground.

BACKGROUND OF THE INVENTION The ileld of this invention is methods and apparatus for driving hollow piles in offshore and other locations.

Heretofore pile driving has generally been eilected by hammering on the pile using mechanical hammers. Attempts have been made to use sonic vibration techniques for pile driving, as disclosed in U.S. Patents Nos. 3,312,- 295; 3, 193,027; and 2,975,846.

'Fluid pressure has been utilized for applying tension to offshore riser pipes as in U.S. Patents Nos. 3,353,851 and 3,465,817, and diilerential pressure has been utilized for joining segments of a subway underwater, as shown in U.S. Pat. No. 2,877,628. However, none of the prior art known to applicant has ever disclosed the concept of driving pile utilizing a developed pressure differential across a baille wit-hin the pile.

SUMMARY OF THE INVENTION The present invention relates to a method and apparatus for driving hollow pile by creating a pressure dillerential across a baille within the pile. In oilshore uses of the invention, the weight of water in the pile above the baille serves as the pressure or force above the baille when the pressure below the baille is reduced by pumping water from such area below the baille. The baille is preferably movable to different positions in the pile so that it can be raised after the pile has been driven downwardly a desired amount. In dry land operation, or other circumstances where the baille in the pile may be out of the water, a pressure differential may be created across the baille by reducing the pressure therebel'ow lower than atmospheric pressure so that the atmospheric pressure above the -baille acts to force the pile downwardly.

It is therefore an object of this invention to provide a new and improved method and apparatus for driving hollow pile or pipe into the ground, either offshore or onshore, by positioning a baille in the pile and then creating a pressure differential across the baille to move the pile.

BRIEF DESCRIPTION `OF THE DRAWINGS FIG. l is a vertical sectional view, partly in elevation, illustrating the preferred form of the apparatus of this invention in position within an hollow pile or pipe;

FIG. 2 is a schematic elevation illustrating the method of this invention wherein an hollow pile or pipe is driven into the ground or bottom within a body of water, such as for an oilshore installation; and

FIG. 3 is a view similar to FIG. 2, but illustrating the pile after it has been driven downwardly into the ground or bottom, using the method and apparatus of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, the letter A designates generally the apparatus of this invention which is adapted to be dis- ICC posed in a pipe or hollow pile P so that upon creating a predetermined pressure diilerential across the apparatus A within the pile P, such pile P is driven downwardly into the ground or bottom G (FIGS. 2 and 3) in a body of water W, or elsewhere. In the preferred form of the invention, water W is coniined within the pipe or pile P above the barrier apparatus A so that the weight of such column of water W acts downwardly on the apparatus A and the pile P for exerting the downward force on the pile P, as will be explained. Also, in the preferred form of the invention, the apparatus A is movable within the pipe P from one secured position to another so that after the pipe or pile P has been forced downwardly with the apparatus A in one position, the apparatus A may be released and moved upwardly to a higher elevation and reattached to the pipe or pile P for subsequently driving the pile P downwardly further into the ground or bottom G.

`Considering the invention more in detail, one form of the invention is illustrated in FIG. 1, although the invention is not limited thereto. Thus, the apparatus A includes a central tubular support or pipe 10 to which are attached a plurality of wheels or rims 12. In some instances, only one of such wheels or rims 12 is provided. In any event, all `of the wheels or rims 12 are welded or otherwise secured to the central support 10. Each rim 12 has an inilatable tire 15 thereon, preferably of the type which Yhas a collapsible wall 15a so that the tire may be inilated to the fully expanded sealing position shown in solid lines in FIG. 1 and may be deflated to the retracted smaller diameter position shown in dotted lines in FIG. l with respect to the upper tire 15 only. The collapsible wall tire is a conventional tire, although it is different than the automobile tires commonly found on automobiles today.

To make the apparatus A movable within the pipe or pile P, the tires or sealing means 15 are connected with a source of 'uid pressure, lpreferably at the surface above the water W. If the pile P is being driven from a platform or derrick iloor, the source of air pressure and the control. valves to the tires 1S are located on the platform or in proximity thereto. As shown in FIG. l, a tube 16 extends downwardly within the pipe or pile P and communicates with an internal passage 12a within the rim 12 so as to establish communication with the interior of the tire 15 on each rim 12. An inner connecting tube section 16a is disposed between the rims 12, or the internal passages 12a are otherwise suitably interconnected so that all of the interiors of the tires 15 are in communication with the tube 16 leading to the upper end of the pile P.

At the upper end of the tube 16, a check'valve 17 is provided for controlling the inlet of air pressure through the line 16 to the tires 15 for inilating such tires 15. The check valve 17 prevents air pressure from moving in the opposite direction towards the source of air pressure (not shown), which may be a suitable air compressor or air pressure tank. A discharge or deflation valve 18 is connected to the tube 16, and it is closed when air pressure is being admitted to the tire 15 through the check valve 17. When it is desired to deilate the tire 15, the check valve 17 prevents iluid ilow towards the compressor or air supply, and the valve 18 is opened to discharge air from the tires 15. When the pressure within each tire 15 is suitably reduced, its wall 15a collapses to the dotted line position shown with respect to the upper tire 15 in FIG. 1 so that the outer diameter of each of the tires 15 is reduced to facilitate the movement 'of the apparatus A through the pipe P.

A barrier plate 20 formed of steel or similar material is welded or is otherwise secured within the central support 10 to close the bore 10a of the tubular support 10. The plate 20 is completely closed across the full cross sectional area of the bore 10a, except for the jet pump 3 tubes 21 and 22 which extend through Stich plate 20 and are welded or are otherwise connected thereto. Also, a relief valve 23, the purpose of which will be hereinafter explained is preferably mounted in the barrier plate 20 for opening to relieve pressure below the plate 20 when it reaches a predetermined amount.

In the preferred form of the invention, a submersible pump 25 having a motor 26 therewith is disposed in the bore a of the central tubular support 10. The pump 25 may be of various types and may be located in places other than illustrated in FIG. l of the drawings but as shown, it is a jet type pump having a jet pump tube 21 which has a jet nozzle 21a so that fluid may be pumped through the tube 21 and discharged through the pump tube 212 to a point above the baille plate to create a reduced pressure in the area below the plate 20.

As will be more fully explained, the tube 22 has a solenoid controlled valve 28 mounted at the discharge end 22a of the tube 22 so as to control the discharge from the pipe 22. A solenoid 28a is schematically shown in FIG. l for operating the valve 25, and it is suitably connected through electrical control wires 28h to an electrical circuit (not shown) which is normally above the upper end of the pile P at the surface platform where the other control equipment is located for handling the apparatus A.

The submersible pump and the motor 26 therewith are preferably resiliently mounted in the bore 10a of the support 10 by a plurality of springs 30 which are secured to the upper end of the motor l26, and by springs 31 which are secured to the lower end of the pump 25. The springs 30 may be Welded or otherwise secured to an annular ring 30a which is welded or otherwise attached to the inside of the support 10. Similarly, the springs 31 may be welded or otherwise secured to a ring 31a which is welded or otherwise secured to the inside of the support 10. The tube 21 should be rubber or other flexible material so that it too may flex should the motor 26 and the pump 25 therewith move longitudinally or vibrate with respect to the central support 10.

The motor 26 is preferably an electric motor which is operable under water and which has suitable electrical wires 26a extending therefrom to a source of electrical power (not shown).

The entire apparatus A is lowered and raised relative to the pipe P when the tires 15 are in the deflated condition, using a wireline or cable 33 (FIG. l) which is secured to the upper end of the support 10 by any suitable connector 10b which is preferably a plate welded across the top of the support 10 without completely closing the bore 10a of the support 10. The electrical wires 26a may pass internally of the cable 33, or they may be carried therewith externally of the cable 33. The cable or wire line 33 extends above the upper end of the pipe or pile P to the platform or other support from which the pile or pipe P is being handled. When the tires 15 are inflated and are thus in the sealing and holding position within the pile P as shown in solid lines in FIG. l, the cable 33 should be maintained in a slack condition by paying same out of the pile P and the apparatus A therewith are lowered.

In a typical use of the apparatus A of this invention and in carrying out the method of this invention, the pipe or hollow pile P is lowered into the body of water W at a suitable offshore location, normally from a floating or fixed barge or platform. The pipe or hollow pile P is lowered in sections and the sections are added using threaded connections or welded connections or any other suitable means for getting the desired length of piling P. It Will be appreciated that during the lowering of the piling P, the water W will enter the bore of the pipe or piling P so as to fill same as indicated at W in FIG. l. After the pile P has been initially positioned in the ground or `bottom G, and has been mechanically forced downwardly by conventional hammers or drive means, if so desired, the apparatus A is then lowered into the interior or bore of the pile or pipe P to a position which is illustrated in FIG. 2. During such lowering of the apparatus A, the weight thereof is suspended on the cable or wire line 33, and the tires 15 are in the deated condition so that they can pass joints and other reduced diameter portions of the piling P. The apparatus A may be positioned at a point very close to the upper surface of the body of water WV, although it is preferable to position the apparatus A at an intermediate point between the upper surface of the water W and the ground G so that a substantial column of water W is present above the apparatus A even during the initial use of the apparatus A for driving the pile P downwardly into the ground G.

With the apparatus A at the desired elevation within the piling P the tires 15 are inflated to the sealing secured position shown in FIG. l so as to constitute the barrier within the pile P. Such barrier thus provided by the tires 15 prevents fluid from passing upwardly or downwardly within the pipe P except to the extent that the pump 25 operates to remove `water or other uid W from below the barrier plate 20. The tires 15 are inflated using air pressure which is transmitted through the check valve 17 and the tube 16, as previously explained.

With the apparatus A thus secured in its first position within the pile P, the pump 25 is operated by starting the motor 26 from a suitable power source and switch at the surface on the platform or other location (not shown). The pump 25 thus discharges a portion of the liquid such as the water W below the barrier 20 upwardly through the open valve 28 and out through the discharge end 22a of the tube. The removal of a portion of the liquid below the plate 20 creates a reduced pressure or a partial vacuum below the plate 20 and within the tube or support 10. This occurs because none of the water W can enter from the bottom of the pipe or pile P` since the lower end of the pipe P is in the ground G. The valve 2i8 is a one-way check valve which prevents water within the pile P above the plate 20 from owing backwardly through the tube 22 into the area below the plate 20.

The reduced pressure or partial vacuum created below the barrier plate 20 thus creates a pressure differential across the plate 20 and also across the uppermost tire 15 throughout the full diameter of the interior of the pile P. The extent of the pressure differential depends upon the weight of the column of water W' above the baffle plate 20 and the uppermost tire 15, and to some extent upon the reduced pressure below the plate 20. The force available is a constant multiplied by the cross sectional area of the pile P, and the cross sectional area of the pile P is a function of its diameter squared. This means that if the diameter of the pile P is doubled Athe force available above the apparatus A is increased by four times. Therefore, the larger the diameter of the pile P, the easier it is to drive the pile P downwardly into the ground or bottom G using the method of this invention. This is extremely important because it means that very large piles P may be driven downwardly using the present method.

The method of this invention may be used in conjunction with conventional hammers or vibrators at the surface which engage the upper end of the piling P in the known manner. If such conventional hammers or vibrators are used they merely assist in the driving force imparted to the pile P through the use of the column or weight of the water or the liquid W' above the apparatus A.

By continuing to remove the water or other liquid from below the plate 20 as the pipe moves downwardly, the pressure differential may be continued across the barrier plate 2t) so that the column of water W continues to force the pile or pipe P downwardly. The water which is removed from below the plate 20 is discharged into the area thereabove so that there is actually little or no water or fluid being discharged from the upper end of the pipe P,

but it is simply being transferred from below the barrier plate 20 to the area thereabove within the pile P.

, When the pipe P descends downwardly, it may develop momentum which causes it to move downwardly faster than water is removed from below the plate 20 by the pump 25. If such should occur, the pressure below the plate 20 may actually increase above that pressure being provided by the column of water above the plate 20 and this tends to stop the downward movement of the pipe P, and even cause it to bounce and move upwardly to some extent. To prevent an excessive bouncing due to such increase in pressure below the plate 20, the relief valve 23 is provided to relieve or pop olf and release some of the pressure from below the plate 20 when it reaches a predetermined amount.

Furthermore, such increase of pressure below the plate 20 may be utilized to reverse the direction of movement of the pipe P to get a vibratory or reciprocatory movement of the pile P for facilitating the jarring or pounding of the pile P into the ground G. The pounding or vibratory movement may be intentionally induced by controlling the opening and closing of the valve 28 so as to intentionally obtain a reversal or upward movement of the pile P alternately or periodically with the downward movements.

When the apparatus A has been moved downwardly with the pile P so that it is near or approaching the ground level of the ground P, the apparatus A may be moved upwardly after first deilating the tires 15. This may be accomplished by opening the valve 18, as previously explained. After the tires 15 are deflated they are no longer in sealing contact with the inside of the pile P and may be lifted upwardly with the cable or wire line 33 to a higher elevation which is approximately at the initial elevation of the apparatus A (FIG. 2). Thereafter, the valve 18 is closed and air is admitted under pressure through the valve 17 to reinflate the tires 15 to again lock the apparatus A with the pipe P for subsequently further driving the pile P downwardly into the ground G. This process is repeated until the desired length of the pile P is within the ground G. It will be apprecited that sections of the pile P are added as the pile P is driven downwardly into the ground G so as to continue to have the desired amount of pile P sticking out above the water W or at such other'elevation as is desired.

Although the invention is illustrated with the pump 25 as the submersible pump above the baille 20, the pump 25 could be below the baffle 20 and could be of any conventional construction for pumping water from the area below the baille 20 outwardly or upwardly to remove water and create a reduced pressure below the barrier plate 20. Also, the motor 25 could be located at the surface on a platform which is disposed above the upper end of the pile P.

Also, although it is preferable to provide a movable barrier such as provided by the tire or tires 15 of the apparatus A, the barrier could be provided by a steel plate welded across the pile P and having a suitable opening through which a pump could be lowered. Since the barrier would thus be fixed in the pile P, the downward movement of the pile P would be limited as compared to the movable barrier apparatus A heretofore described.

Also, instead of utilizing water W' within the pipe P, the apparatus A may be located within the pile P with only atmospheric air pressure above the apparatus A, and a partial vacuum may then be created below the barrier plate 20 so as to create the pressure differential with only the atmospheric air acting downwardly on the apparatus A for the driving force. Such atmospheric pressure is of course not as great a factor as the column of water W but it does provide a substantial downward force, depending upon the area acted upon and it may be effective in driving the pipe alone or in combination with conventional hammering and driving techniques. Also, the density of the liquid above the apparatus A within the pile P may be increased by using weighted fluids or mud instead of water so as to further increase the force downwardly on the pile P.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made Without departing from the spirit of the invention.

I claim:

1. An apparatus for moving an hollow pile downwardly relative to the ground, comprising:

a central tubular support adapted to be disposed in the hollow pile at an elevation above ground level with an annulus formed therebetween;

a barrier disposed in said central support and closing the bore of said tubular support;

releasable, inflatable and deflatable, annular seal means disposed on the exterior of said tubular support for sealing engagement with the inner wall of the hollow pile to seal off said annulus between said support and the hollow pile; and

means for reducing the pressure in said tubular support below said barrier to an amount less than the pressure thereabove to thereby exert a force to move the pile downwardly in the direction of the lower pressure side of said barrier.

2. The structure set forth in claim 1, wherein said means for creating a pressure differential includes:

a pump means having pipe means therewith for establishing iluid communication below said barrier to pump lluid from below said barrier.

3. The structure set forth in claim 1, wherein said seal means includes:

an automobile tire adapted to be inflated and deflated to and from a non-sealing position and sealing contact with the inside of said pile.

4. The structure set forth in claim 1, wherein said seal means includes:

a plurality of inflatable and deilatable automobile tires mounted on said central support; and

each of said tires being collapsible upon deflation to a reduced diameter in said non-sealing position to facilitate longitudinal movement thereof in the pile.

5. The structure set forth in claim 2, wherein:

said pump means is mounted on said central support;

and

a valve is provided with said pipe means for controlling the discharge from said pump means.

References Cited UNITED STATES PATENTS 2,775,869 1/1957 Pointer 6l-46.5 3,400,967 9/ 1968 Heller et al. 294-93 3,406,524 10/ 1968 Blenkarn et al. 6153.5 3,314,240 4/ 1967 Bardgette 61-46.5 X 3,380,256 4/ 1968 Rebikolf 61-465 JACOB SHAPIRO, Primary Examiner U.S. Cl. X.R. 

